These Instructions are for iPhone users running IOS 10 or earlier. For the IOS 11 / iPhone 8 instructions please follow these instructions. For IOS 12 please follow these instructions.
1. Click on Settings
2. Click on Mail, Contacts, Calendars
3. Click on Add Account
4. Click on Exchange
5. Enter your email address and password then click on next
6. (Optional) – If this screens pops up enter outlook.office365.com in the server field
7. Choose what you would like synced with Office 365 and your iPhone and then click on save